Controller of hybrid vehicle

ABSTRACT

A control apparatus and method for a hybrid vehicle that judges whether the vehicle is running on a congested road based on an output from a sensor, causes a take-off from a first state where a gear ratio of an automatic transmission is large at a time of taking-off when running on the congested road, causes the take-off from a second state where the gear ratio of the automatic transmission is small at the time of taking-off when not running on the congested road and replenishes, by driving a motor/generator, a part of an under torque of the driving source created by taking-off from a state where the gear ratio of the automatic transmission is large, when a temporary high acceleration take-off request is made while a judgment of congested road running is maintained

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to a control apparatus of a hybridvehicle that uses an internal combustion engine and a motor/generator asa driving source.

[0003] 2. Description of Related Art

[0004]FIG. 17 is a time chart showing one example of downshift disablingcontrol on a congested road in a prior art, and FIG. 18 is a time chartshowing one example of control at the time of throttle actuation underdownshift disabling control on a congested road in a prior art.

[0005] Normally, on a congested road, a take-off/stop is repeatedfrequently, and concomitantly, an upshift/downshift is also repeatedfrequently, that is, a busy-shift state arises, so that ride qualitydeteriorates. To prevent occurrence of such busy shifting, in the caseof being judged as a congested road, congested road control thatdisables downshift to first or to second or lower and takes-off at ashift speed of second or higher at all times has been conventionallycarried out.

[0006] However, when a driver feels a need to accelerate and actuates athrottle more than a specified amount, conventional congested roadcontrol on a congested road is canceled as shown in FIG. 18 (a time T1),and thereafter, normal shift control with downshift is executed.Therefore, for a case in which a congested state continues thereafter,busy shifting occurs.

[0007] Moreover, under congested road control, as shown in FIG. 17, avehicle speed is a low speed, and when taking-off, a vehicle takes-offat a high shift speed, and output on an internal combustion engine sideis maintained in a low torque state, so that for a case in which suchcontrol is applied to a hybrid vehicle as it is, there are fewopportunities that a motor/generator performs a regenerating operationand charges a battery. Therefore, SOC decreases, and a need for chargingthe battery when the vehicle stops occurs, so that a problem occurs inwhich the idle stop control for stopping the internal combustion enginewhen the vehicle stops, which is a characteristic of a hybrid vehicle,is difficult to execute.

[0008] Accordingly, an object of the present invention is to provide acontrol apparatus for a hybrid vehicle which, in a hybrid vehicle, doesnot cancel congested road control immediately even when a throttle isactuated under congested road control, and enables charge (regeneration)of the battery even under congested road control.

SUMMARY OF THE INVENTION

[0009] An invention of claim 1, in a hybrid vehicle in which an internalcombustion engine and a motor/generator connected to the internalcombustion engine are used as a driving source, an automatictransmission connected to the driving source is disposed, axles areconnected to the automatic transmission, a sensor for detecting arunning state of the vehicle is disposed, a congested road judging meansfor judging whether the vehicle is running on a congested road or notbased on output from the sensor is provided, and a take-off controlmeans for controlling so as to cause to takeoff from a state where agear ratio of the automatic transmission is large at the time oftaking-off in the case of being judged by said congested road judgingmeans as running on a congested road and controlling so as to cause totake-off from a state where a gear ratio of the automatic transmissionis small at the time of taking-off in the case of being not judged asrunning on a congested road is provided, wherein a control apparatus ofthe hybrid vehicle, constructed so as to have under torque replenishingmeans which replenishes, by driving of said motor/generator, a part ofan under torque of the driving source arisen when caused to take-offfrom a state where a gear ratio of the automatic transmission is largeby the take-off control means, for a case in which a temporary highacceleration take-off request is made while a judgment of congested roadrunning by the congested road judging means is maintained.

[0010] Thereby, at the time of temporary acceleration during congestedrunning, the under torque replenishing means replenishes the undertorque portion of the driving source using the drive of themotor/generator, so that even for a case in which a temporary highacceleration take-off request is made during congested road running, itis possible to perform a take-off operation without a sense ofdiscomfort by maintaining the take-off operation from a state in whichthe gear ratio of the automatic transmission is large. Also,consequently, since there is no need to cancel congested road control,in congested road running thereafter, taking-off from a state in whichthe gear ratio of the automatic transmission is small is prevented, andbusy shifting is prevented.

[0011] An invention of claim 2 is constructed so as to provide thecongested road judging means with a temporary high acceleration judgingmeans which judges whether or not to maintain a judgment of congestedroad running by the congested road judging means for a case in which atemporary acceleration take-off state during congested road runningarises.

[0012] Thereby, the temporary acceleration judging means judges whetheror not to maintain a judgment of congested road running by the congestedroad judging means for a case in which a temporary high accelerationtake-off request is made, so the cancellation of the congested roadjudgment simply at a time when the high acceleration take-off requestoccurs is prevented, and take-off control with even less sense ofdiscomfort is enabled.

[0013] An invention of claim 3 is constructed so as to be characterizedin that the under torque replenishing means has an output map of themotor/generator associated with a throttle angle, and determines thetorque to replenish by the drive of the motor/generator based on theoutput map.

[0014] Thereby, based on the output map of the motor/generator thatcorresponds to a throttle angle, it is possible to easily find torque toreplenish by the drive of the motor/generator, and control isfacilitated.

[0015] An invention of claim 4, in the invention according to claim 3,is constructed so that the output map has an output map of themotor/generator that corresponds to a throttle angle and a vehiclespeed.

[0016] Thereby, it is possible to adapt the output map to a drivingcondition of the vehicle.

[0017] An invention of claim 5 is constructed so that, in the inventionaccording to claim 3, the output map has an output map of themotor/generator that corresponds to a throttle angle and a motorrevolution.

[0018] Thereby, it is possible to adapt the output map to the drivingcondition of the vehicle.

[0019] An invention of claim 6 is constructed so as to have an actuationcontrol means during congestion that shifts an actuating condition ofthe internal combustion engine to a high vehicle speed side while ajudgment of congested road running is maintained by the congested roadjudging means.

[0020] Thereby, since the actuation control means during congestionshifts an actuating condition of the internal combustion engine to ahigh vehicle speed side while a judgment of congested road running ismaintained by the congested road judging means, it is difficult toactivate the internal combustion engine, and thereby because torqueassist by the motor/generator is enabled, the internal combustion enginecan be activated in a state where the gear ratio of the automatictransmission is large, and it is possible to prevent busy shifting.

[0021] An invention of claim 7, in the invention according to claim 1,is constructed so as to be characterized in that the automatictransmission is an automatic stepped transmission which has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on an engagement stateof the friction engagement elements, and differentiates the gear ratioby switching the shift speeds.

[0022] Thereby, since the automatic stepped transmission has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on an engagement stateof the friction engagement elements, it is possible to differentiate agear ratio by switching the shift speeds. As a result, combined withdrive of the motor/generator, it becomes possible to prevent busyshifting.

[0023] An invention of claim 8, in the invention according to claim 1,is constructed so as to be characterized in that the automatictransmission is an automatic continuously variable transmission whichhas a pair of pulleys and a power transmission belt held tight by thepulleys and differentiates a gear ratio based on a pulley width of thepulleys.

[0024] Thereby, since the automatic continuously variable transmissionhas a pair of pulleys and a power transmission belt held tight by thepulleys, it is possible to differentiate the gear ratio based on thepulley width of the pulleys. As a result, combined with the drive of themotor/generator, it becomes possible to prevent busy shifting.

[0025] An invention of claim 9, in a hybrid vehicle in which an internalcombustion engine and a motor/generator connected to the internalcombustion engine are used as a driving source, an automatictransmission connected to the driving source is disposed, the vehicleaxles are connected to the automatic transmission, a sensor fordetecting a running state of the vehicle is disposed, and a congestedroad judging means for judging whether the vehicle is running on acongested road or not based on output from the sensor is provided, isconstructed so as to have a regeneration control means which, for a casein which the congested road judging means judges that the vehicle isrunning on a congested road, causes the automatic transmission toperform normal shifting at the time of take-off by the internalcombustion engine and consequently to perform a regenerating operationby driving the motor/generator with extra torque produced from theinternal combustion engine at the time of take-off.

[0026] Thereby, for a case in which the congested road judging meansjudges that the vehicle is running on a congested road, it is possibleat the time of take-off by the internal combustion engine to cause theautomatic transmission to perform normal shifting and perform aregenerating operation by driving the motor/generator with extra torqueproduced from the internal combustion engine at the time of take-off. Itis possible to charge a battery, ensure a sufficient SOC, andeffectively execute idle stop control, which is a characteristic of ahybrid vehicle.

[0027] An invention of claim 10, in the invention according to claim 9,is constructed so as to have an idle stop control disabling means whichdisables the control for stopping the internal combustion engine whenthe vehicle stops for a case in which the congested road judging meansjudges that the vehicle is running on a congested road.

[0028] Thereby, the idle stop control disabling means disables idle stopcontrol during congested road running, whereby it is possible toeffectively charge the battery.

[0029] An invention of claim 11, in the invention according to claim 9,is constructed so as to be characterized in that an SOC monitoring meanswhich monitors the SOC of a battery is disposed and the regenerationcontrol means is driven for a case which the SOC monitored by the SOCmonitoring means is less than a specified value.

[0030] Thereby, since the regeneration control means is driven for acase in which the SOC monitored by the SOC monitoring means is less thana specified value, the battery is charged by regeneration of themotor/generator only when necessary. Therefore, for a case in which theSOC is large and there is no need to charge, it is possible to executeidle stop control, and it is possible to maximize a feature of a hybridvehicle.

[0031] An invention of claim 12, in the invention according to claim 9,is constructed so as to be characterized in that the automatictransmission is an automatic stepped transmission which has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on an engagement stateof the friction engagement elements, and differentiates a gear ratio byswitching the shift speeds.

[0032] Thereby, since the automatic stepped transmission has a pluralityof friction engagement elements and the gear mechanism forming aplurality of shift speeds that shift input rotation based on theengagement state of the friction engagement elements, it is possible todifferentiate the gear ratio by switching the shift speeds. As a result,combined with the drive of the motor/generator, charging of the batteryand so on are enabled.

[0033] An invention of claim 13, in the invention according to claim 9,is constructed so as to be characterized in that the automatictransmission is an automatic continuously variable transmission whichhas a pair of pulleys and a power transmission belt held tight by thepulleys and differentiates the gear ratio based on the pulley width ofthe pulleys.

[0034] Thereby, since the automatic continuously variable transmissionhas a pair of pulleys and a power transmission belt held tight by thepulleys, it is possible to differentiate the gear ratio based on thepulley width of the pulleys. As a result, combined with driving of themotor/generator, charging of the battery and so on are enabled.

[0035] An invention of claim 14 is constructed so as to have a runningstate judging means which judges whether the internal combustion engineand the automatic transmission are in a warming-up state or not, and anactuation control switching means which controls so as to execute aregenerating operation by the regeneration control means according toclaim 9 when the vehicle takes-off during congested road running for acase in which the running state judging means judges the internalcombustion engine and automatic transmission as being in a warming-upstate, and executes an under torque replenishing operation by the undertorque replenishing means according to claim 1 when the vehicletakes-off during congested road running for a case in which the runningstate judging means judges the internal combustion engine and automatictransmission as being in a normal running state.

[0036] Thereby, since the actuation control switching means selects andexecutes a regenerating operation or the under torque replenishingoperation in response to the warming-up state of the internal combustionengine and the automatic transmission, optimum control that isresponsive to a state of the vehicle is enabled.

[0037] An invention of claim 15, in the invention according to claim 14,is constructed so as to be characterized in that the running statejudging means judges from at least one of an oil temperature and a watertemperature of the internal combustion engine and an oil temperature ofthe automatic transmission whether the internal combustion engine andautomatic transmission are in a warming-up state or not.

[0038] Thereby, since it is judged from at least one of the oiltemperature and the water temperature of the internal combustion engineand the oil temperature of the automatic transmission whether theinternal combustion engine and automatic transmission are in awarming-up state or not, an appropriate judgment is enabled.

[0039] An invention of claim 16, in the invention according to claim 14,is constructed so as to be characterized in that the automatictransmission is an automatic stepped transmission which has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on an engagement stateof the friction engagement elements and differentiates the gear ratio byswitching the shift speeds.

[0040] Thereby, since the automatic stepped transmission has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on the engagement stateof the friction engagement elements, it is possible to differentiate thegear ratio by switching the shift speeds. As a result, combined with thedrive of the motor/generator, it is possible, for example, to preventbusy shifting and charge the battery.

[0041] An invention of claim 17, in the invention according to claim 14,is constructed so as to be characterized in that the automatictransmission is an automatic continuously variable transmission whichhas a pair of pulleys and a power transmission belt held tight by thepulleys and differentiates the gear ratio based on the pulley width ofthe pulleys.

[0042] Thereby, since the automatic continuously variable transmissionhas a pair of pulleys and a power transmission belt held tight by thepulleys, it is possible to differentiate the gear ratio based on thepulley width of the pulleys. As a result, combined with the drive of themotor/generator, it is possible, for example, to prevent busy shiftingand charge the battery.

[0043] An invention of claim 18 is constructed so as to have a batterystate judging means which judges the state of the SOC of the batterythat drives the motor/generator, and an actuation control switchingmeans which controls so as to execute a regenerating operation by theregeneration control means according to claim 9 when the vehicletakes-off during congested road running for a case in which the batterystate judging means judges the SOC of the battery as being equal to orless than a defined value, and executes an operation for replenishingunder torque by the under torque replenishing means according to claim 1when the vehicle takes-off during congested road running in the case ofjudging the SOC of the battery as being equal to or more than thedefined value.

[0044] Thereby, the actuation control switching means controls so as toexecute the regenerating operation by the regeneration control meanswhen the vehicle takes-off during congested road running for a case inwhich the SOC of the battery is judged as being equal to or less than adefined value, and executes the under torque replenishing operation bythe under torque replenishing means when the vehicle takes-off duringcongested road running for a case in which the SOC of the battery isjudged as being equal to or more than the defined value, so that theappropriate control is allowed in response to the battery state.

[0045] An invention of claim 19, in the invention according to claim 18,is constructed so as to be characterized in that the automatictransmission is an automatic stepped transmission which has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on the engagement stateof the friction engagement elements and differentiates the gear ratio byswitching the shift speeds.

[0046] Thereby, since the automatic stepped transmission has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on an engagement stateof the friction engagement elements, it is possible to differentiate thegear ratio by switching the shift speeds. As a result, combined withdriving of the motor/generator, it is possible, for example, to preventbusy shifting and charge the battery.

[0047] An invention of claim 20, in the invention according to claim 18,is constructed so as to be characterized in that the automatictransmission is an automatic continuously variable transmission whichhas a pair of pulleys and a power transmission belt held tight by thepulleys and differentiates the gear ratio based on the pulley width ofthe pulleys.

[0048] Thereby, since the automatic continuously variable transmissionhas a pair of pulleys and a power transmission belt held tight by thepulleys, it is possible to differentiate the gear ratio based on thepulley width of the pulleys. As a result, combined with the drive of themotor/generator, it is possible, for example, to prevent busy shiftingand charge the battery.

BRIEF DESCRIPTION OF THE DRAWINGS

[0049]FIG. 1 is a block pattern diagram showing a driving system of avehicle relating to the present invention, FIG. 2 is a view showing anautomatic speed change mechanism applied to the present invention, inwhich (a) is a skeleton view of the automatic speed change mechanism and(b) is an operation table thereof, FIG. 3 is a block diagram showing acontrol system of a hybrid vehicle, FIG. 4 is a flowchart showing oneexample of a congested road judgment program, FIG. 5 is a flowchartshowing one example of a congested road control program, FIG. 6 is aview showing one example of a shifting line view, FIG. 7 is an outputmap showing a relation between a motor revolution and a motor torquevalue, FIG. 8 is a view showing a relation of a throttle angle, a shiftgear speed, a vehicle output and a vehicle speed when torque assist by amotor/generator is not used, FIG. 9 is a view showing a relation of athrottle angle, a shift gear speed, vehicle output and a vehicle speedwhen torque assist by the motor/generator is used, FIG. 10 is a mapshowing one example of a motor torque output limitation value on aregeneration side, FIG. 11 is a view showing a relation of the throttleangle, the shift gear speed, the vehicle output and the vehicle speed atthe time of normal running during which a regenerating operation is notcarried out by the motor/generator, FIG. 12 is a view showing a relationof the throttle angle, the shift gear speed, the vehicle output and thevehicle speed at the time when the regenerating operation is carried outby the motor/generator, FIG. 13 is a skeleton view showing acontinuously variable speed change mechanism 5 applied to the presentinvention, FIG. 14 is a flowchart showing one example of a congestedroad control program, FIG. 15 is a view showing a relation of thethrottle angle, a pulley ratio, the vehicle output and the vehicle speedwhen using torque assist by the motor/generator, FIG. 16 is a viewshowing a relation of the throttle angle, the pulley ratio, the vehicleoutput and the vehicle speed at the time when the regenerating operationis carried out by the motor/generator, FIG. 17 is a time chart showingone example of downshift disabling control on a congested road in aprior art, and FIG. 18 is a time chart showing one example of control atthe time of throttle actuation under downshift disabling control on acongested road in a prior art.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0050] Below, a first embodiment relating to the present invention willbe described with reference to the drawings.

[0051]FIG. 1 is a block pattern diagram showing a driving system of avehicle relating to the present invention, FIG. 2 is a view showing anautomatic speed change mechanism applied to the present invention, inwhich (a) is a skeleton view of the automatic speed change mechanism and(b) is an operation table thereof, FIG. 3 is a block diagram showing acontrol system of a hybrid vehicle, FIG. 4 is a flowchart showing oneexample of a congested road judgment program, FIG. 5 is a flowchartshowing one example of a congested road control program, FIG. 6 is aview showing one example of a shifting line view, FIG. 7 is an outputmap showing a relation between a motor revolution and a motor torquevalue, FIG. 8 is a view showing a relation of a throttle angle, a shiftgear speed, a vehicle output and a vehicle speed when torque assist by amotor/generator is not used, FIG. 9 is a view showing a relation of athrottle angle, a shift gear speed, vehicle output and a vehicle speedwhen torque assist by the motor/generator is used, FIG. 10 is a mapshowing one example of a motor torque output limitation value on aregeneration side, FIG. 11 is a view showing a relation of the throttleangle, the shift gear speed, the vehicle output and the vehicle speed atthe time of normal running during which a regenerating operation is notcarried out by the motor/generator, FIG. 12 is a view showing a relationof the throttle angle, the shift gear speed, the vehicle output and thevehicle speed at the time when the regenerating operation is carried outby the motor/generator.

[0052] As shown in FIG. 1, a driving source of a hybrid vehicle consistsof an engine 2 and a motor/generator (M/G) 3 which are mounted on abody, output shafts of the engine 2 and the motor/generator 3 aredirectly coupled, and a driving force thereof is output to an automaticspeed change mechanism 5 via a torque converter (T/C) 4 which forms anautomatic transmission.

[0053] Further, the automatic speed change mechanism 5 that is connectedwith the engine 2 and the motor/generator (M/G) 3 shown in FIG. 1 shiftsan input driving force based on a specified vehicle running condition,and outputs to wheels and so on. Moreover, in the automatic speed changemechanism 5, a plurality of friction engagement elements for shiftingare positioned, and a hydraulic control unit 6 for shifting by hydrauliccontrol of engagement of the friction engagement elements andcontrolling the aforementioned torque converter 4 is provided. Amechanical oil pump 7 and an electric oil pump 8 for supplying oilpressure to the hydraulic control unit 6 are positioned, respectively.The mechanical oil pump 7 is positioned so as to interlock the torqueconverter 4 and driven by a driving force of the engine 2 and themotor/generator 3. Moreover, the electric oil pump 8 is independent froma driving force of the engine 2 and the motor/generator 3, and driven bya motor to which electric power is supplied from a battery not shown inthe drawings.

[0054] Next, the automatic speed change mechanism will be described withreference to the drawings. FIG. 2 is a view showing the automatic speedchange mechanism 5 applied to the present invention, in which (a) is askeleton view of the automatic speed change mechanism 5 and (b) is anoperation table thereof. As shown in FIG. 2(a), a main automatic speedchange mechanism 30 is placed on a first shaft placed in line with anengine output shaft, and provided with an input shaft 37 to which adriving force is transmitted from the engine 2 (E/G) and themotor/generator (M/G) 3 via the torque converter 4 having a lock-upclutch 36. On the first shaft, the mechanical oil pump 7 and electricoil pump 8 adjacent to the torque converter 4, a brake portion 34, aplanetary gear unit portion 31 and a clutch portion 35 are placed inthis order.

[0055] The planetary gear unit portion 31 consists of a simple planetarygear 32 and a double-pinion planetary gear 33. The simple planetary gear32 is composed of a sun gear S1, a ring gear R1, and a carrier CRsupporting a pinion P1 meshed with the gears, and the double-pinionplanetary gear 33 is composed of a sun gear S2, a ring gear R2, and thecarrier CR supporting a pinion P2 meshed with the sun gear S2 and apinion P3 meshed with the ring gear R2 so as to mesh together. The sungear S1 and the sun gear S2 are supported so as to be rotatable on ahollow shaft supported so as to be rotatable on the input shaft 37,respectively. Moreover, the carrier CR is common to both the planetarygears 32 and 33, and the pinion P1 and the pinion P2 meshed with the sungears S1 and S2, respectively, are coupled so as to rotate in anintegrated manner.

[0056] In the brake portion 34, a one-way clutch F1, a brake B1 and abrake B2 are positioned in this order from an inside diameter side to anoutside diameter direction, and a counter drive gear 39 is coupled tothe carrier CR via a spline. Also, a one-way clutch F2 is interposedbetween the ring gear R2 and a case, and a brake B3 is interposedbetween the outside periphery of the ring gear R2 and the case. Inaddition, the clutch portion 35 is provided with a forward clutch C1 anda direct clutch C2, the forward clutch C1 is interposed in the outsideperiphery of the ring gear R1, and the direct clutch C2 is interposedbetween the inside periphery of a moving member not shown in thedrawings and a flange portion coupled to a tip of the hollow shaft.

[0057] A secondary speed change mechanism 40 is positioned on a secondshaft 43 placed in parallel with the first shaft made by the input shaft37, and the first shaft and the second shaft are constructed like atriangle from the side view together with a third shaft made bydifferential shafts (left and right axles) 45 l and 45 r. The secondaryspeed change mechanism 40 has simple planetary gears 41 and 42, and acarrier CR3 and a ring gear R4 are coupled in an integrated manner andsun gears S3 and S4 are coupled to each other in an integrated manner,thereby constructing a Simpson type gear line. Also, the ring gear R3 iscoupled to a counter driven gear 46 to construct an input portion, andthe carrier CR3 and the ring gear R4 are coupled to a decelerating gear47, which is an output portion. Furthermore, a UD direct clutch C3 isinterposed between the ring gear R3 and the integrated sun gears S3 andS4, the integrated sun gear S3 (S4) can be locked by a brake B4 asnecessary, and a carrier CR4 can be locked by a brake B5 as necessary.Consequently, the secondary speed change mechanism 40 is capable ofobtaining shift speeds of three forward speeds.

[0058] Moreover, a differential unit 50 constructing the third shaft hasa differential case 51, and a gear 52 meshed with the decelerating gear47 is fixed to the case 51. Furthermore, inside the differential case51, a differential gear 53 and left and right side gears 55 and 56 aremutually meshed and supported so as to be rotatable, and the left andright axles 45 l and 45 r are extended from the left and right sidegears. Consequently, rotation from the gear 52 is branched in responseto load torque, and transmitted to left and right front wheels via theleft and right axles 45 l and 45 r.

[0059] Next, an operation of the automatic speed change mechanism 5 willbe described with the operation table shown in FIG. 2(b). In the first(1ST) state, the forward clutch C1, the one-way clutch F2 and the brakeB5 are engaged. Consequently, the main speed change mechanism 30 comesto 1ST, and the deceleration rotation is transmitted to the ring gear R3in the secondary speed change mechanism 40 via the counter gears 39 and46. The secondary speed change mechanism 40 is in the 1ST state as aresult of the carrier CR4 being stopped by the brake B5, and thedeceleration rotation of the main speed change mechanism 30 is furtherdecelerated by the secondary speed change mechanism 40 and transmittedto the axles 45 l and 45 r via the gears 47 and 52 and the differentialunit 50.

[0060] In the second (2ND) state, other than the forward clutch C1, thebrake B2 is engaged, and the one-way clutch F2 smoothly switches to theone-way clutch F1, whereby the main speed change mechanism 30 comes tothe 2ND state. Moreover, the secondary speed change mechanism 40 is inthe 1ST state because of engagement of the brake B5, and by combinationof the 2ND state and the 1ST state, 2ND can be obtained in the entireautomatic speed change mechanism 5.

[0061] In the third (3RD) state, the main speed change mechanism 30 isin the same state as the aforementioned 2ND state that the forwardclutch C1, the brake B2 and the one-way clutch F1 are engaged, and thesecondary speed change mechanism 40 engages the brake B4. Then, the sungears S3 and S4 are fixed, and the rotation from the ring gear R3 isoutput from the carrier CR3 as the 2ND rotation, so that 3RD can beobtained in the entire automatic speed change mechanism 5 from 2ND ofthe main speed change mechanism 30 and 2ND of the secondary speed changemechanism 40.

[0062] In the fourth (4TH) state, the main speed change mechanism 30 isin the same state as the aforementioned 2ND and 3RD states in which theforward clutch C1, the brake B2 and the one-way clutch F1 are engaged,and the secondary speed change mechanism 40 releases the brake B4 andengages the UD direct clutch C3. In this state, the ring gear R4 and thesun gear S3 (S4) are coupled and both the planetary gears 41 and 42directly rotate in an integrated manner. Therefore, 2ND of the mainspeed change mechanism 30 and direct coupling (3RD) of the secondaryspeed change mechanism 40 are combined, whereby the 4TH rotation can beobtained in the entire automatic speed change mechanism 5.

[0063] In the fifth (5TH) state, the forward clutch C1 and the directclutch C2 are engaged, and rotation of the input shaft 37 is transmittedto both the ring gear R1 and the sun gear S1, whereby the gear unit 31of the main speed change mechanism 30 directly rotates in an integratedmanner. Moreover, the secondary speed change mechanism 40 is in directrotation with the UD direct clutch C3 engaged, so that 3RD (directcoupling) of the main speed change mechanism 30 and 3RD (directcoupling) of the secondary speed change mechanism 40 are combined, andthe 5TH rotation can be obtained in the entire automatic speed changemechanism 5.

[0064] In a reverse (REV) state, in addition to the direct clutch C2 andthe brake B3, the brake B5 is engaged as well. In this state, reverserotation is produced in the main speed change mechanism 30, and thesecondary speed change mechanism 40 is maintained in the 1ST state as aresult of the carrier CR4 stopping based on the brake B5. Therefore,reverse rotation of the main speed change mechanism 30 and the 1STrotation of the secondary speed change mechanism 40 are combined,whereby reverse deceleration rotation can be obtained.

[0065] In FIG. 2(b), a triangle mark shows operation at the time ofengine brake. More specifically, in 1ST, the brake B3 is engaged,thereby fixing the ring gear R2 instead of the one-way clutch F2. In2ND, 3RD and 4TH, the brake B1 is engaged, thereby fixing the sun gearS2 instead of the one-way clutch F1.

[0066] Moreover, as shown in FIG. 3, a motor control unit 12 whichcontrols the motor/generator 3 is connected to the vehicle, and avehicle control unit 13, a transmission control unit 15 and so on areconnected to the motor control unit 12.

[0067] Since the hybrid vehicle has a construction as described above,while the vehicle is running, the vehicle control unit executes acongested road judgment program JJP shown in FIG. 4 at all times, judgeswhether a present running state is congested road running or not, and,in the case of judging as currently running on a congested road,executes a congested road control program JCP described later.

[0068] More specifically, at step S1 of the congested road judgmentprogram JJP, it is judged whether a congested road judgment flag is ONor not. Since an initial value of the congested road judgment flag isnormally OFF, a congested road judgment operation is started at step S2.

[0069] At step S3, it is judged whether a throttle angle is less than adefined value ‘1’ or not. For a case in which the throttle angle is lessthan the defined value ‘1’, that is, a low throttle angle, a counter ‘1’is incremented by one at step S4, and for a case in which the throttleangle is equal to or more than the defined value ‘1’, that is, not a lowthrottle angle, the counter ‘1’ is decremented by one or cleared at stepS5.

[0070] Next, at step S6, it is judged whether a present average vehiclespeed is less than a defined value ‘2’ or not. For a case in which apresent average vehicle speed is less than the defined value ‘2’, thatis, in the case of low-speed running, count of a timer ‘1’ is started atstep S7, and for a case in which a present average vehicle speed isequal to or more than the defined value ‘2’, that is, in the case whennot low-speed running, count of the timer ‘1’ is cleared at step S8.

[0071] Next, at step S19, it is judged whether or not the timer ‘2’ isover a defined value ‘7’ and the counter ‘2’ is over a defined value‘8’. For a case in which the timer ‘2’ is equal to or more than thedefined value ‘7’ and the counter ‘2’ is equal to or more than thedefined value ‘8’, that is, for a case in which a high throttle anglefor which a throttle angle is equal to or more than the defined value‘7’ has continued to some extent and a high vehicle speed state forwhich an average vehicle speed is equal to or more than the definedvalue ‘8’ has continued for a specified time or more, the congested roadjudgment flag is turned OFF and a present running state of the vehicleis judged as being out of congested road running and coming to a normalrunning state at step S20. The congested road judgment program JJPclears the timer ‘2’ and the counter ‘2’ at step S21, and makes readyfor re-execution of the congested road judgment program JJP.

[0072] Thus, for a case in which the congested road judgment program JJPis executed and the congested road judgment flag is turned ON, thevehicle control unit 13 executes the congested road control program JCPshown in FIG. 5.

[0073] The congested road control program JCP, at step S30, checkswhether the congested road judgment flag is ON or not, and at step S31,judges whether an oil temperature of the engine 2 is equal to or morethan a defined value ‘6’ (a temperature at which an engine oiltemperature reaches a normal temperature: for example, about 30° C.),whether a water temperature of the engine 2 is equal to or more than adefined value ‘7’ (a temperature at which an engine water temperaturereaches a normal temperature: for example, about 30° C.), whether an oiltemperature of the automatic speed change mechanism 5 is equal to ormore than a defined value ‘8’ (a temperature at which the oiltemperature of the automatic speed change mechanism reaches a normaltemperature: for example, about 30° C.) and whether an SOC of thebattery is equal to or more than a defined value ‘9’ (a degree thattorque assist described later can be performed several times at the timeof idle stop control: for example, about 40%), that is, judges a stateof a driving portion of the hybrid vehicle.

[0074] In other words, for a case in which the oil temperature of theengine 2 is over the defined value ‘6’, the water temperature of theengine 2 is over the defined value ‘7’, the oil temperature of theautomatic speed change mechanism 5 is over the defined value ‘8’ or theSOC of the battery is over the defined value ‘9’, the engine 2 is in anormal running state, and a charge capacity of the battery driving themotor/generator 3 is sufficient, so that a busy-shifting preventionoperation by torque assist using the motor/generator 3 described lateris performed. Moreover, at step S31, a case where the oil temperature ofthe engine 2 is equal to or less than the defined value ‘6’, the watertemperature of the engine 2 is equal to or less than the defined value‘7’, the oil temperature of the automatic speed change mechanism 5 isequal to or less than the defined value ‘8’ or the SOC of the battery isequal to or less than the defined value ‘9’ (it is preferable to useAND/OR of a forming condition of these parameters in combination asnecessary according to a condition of the vehicle) is a case wherewarming-up is necessary because the engine 2 and the automatic speedchange mechanism 5 have just been actuated and so on, and furthermore, acase where the SOC of the battery is low and torque assist by the use ofthe motor/generator 3 cannot be sufficiently performed, so that controlis executed in a manner that warming-up of the engine 2 and a chargingoperation to increase the SOC of the battery take priority over abusy-shifting prevention operation as described later.

[0075] More specifically, in the case of performing a busy-shiftingprevention operation by torque assist using the motor/generator 3 atstep S31, conditions at the time of idle stop are changed at step S32.In other words, various kinds of parameters during idle stop which stopthe engine 2 when the vehicle stops and stop the idling of engine 2 arechanged, in consideration of congested conditions, so that the engine isas difficult to start as possible and the vehicle can run using themotor/generator 3 when it begins to move. Specifically, for example, anactuation condition of the engine 2 is changed from a vehicle speed of 0Km/h to 10 Km/h, and actuation of the engine 2 by brake-off is stopped.

[0076] Next, at step S33, a shifting line is changed from a state of asolid line shown in FIG. 6 to a state of a dashed line so that shiftingat a low vehicle speed is performed during congested conditions andoutput torque from the driving source (the engine or themotor/generator) becomes small. Instead of changing the shifting line,downshift to a lower speed may be disabled (for example, a downshiftdisabling region may be changed in response to a vehicle speed in such amanner so that downshift to 2ND or lower, 3RD or lower, or 4TH or loweris disabled).

[0077] Next, at step S34, output torque of the motor/generator 3 thatcorresponds to the throttle angle and the motor/generator revolution isfound from a torque output map of the motor/generator shown in FIG. 7.When the throttle angle and a revolution of the engine 2 (that is, arevolution of the motor/generator 3) at present are ascertained fromthis output map, torque to be assisted by the motor/generator 3 isimmediately ascertained. Regarding output of the motor/generator 3, fromthe throttle angle and the vehicle speed, or only from the throttleangle, output torque may be found by the use of specified maps,respectively.

[0078] Next, at steps S35 and S36, the motor control unit 12 is directedto perform torque assist to the engine 2.

[0079] More specifically, for example, as shown in FIG. 8, both for acase in which a throttle angle becomes Th1 and for a case in which itbecomes Th2 larger than Th1 as a result of the throttle being actuatedin a congested road judgment flag ON state, as described regarding stepS33, the congested road judgment flag is ON, therefore, downshift isdisabled by the transmission control unit 15, and the shift speed isfixed to 3RD, which is a high shift speed (that is, a state in which thegear ratio is large). Despite take-off in 3RD regardless of the throttleangle, because the take-off is on a congested road the take-off at lowtorque is slow.

[0080] In the case of a small throttle angle Th1, a driver is notintending to rapidly accelerate the vehicle, and therefore, there is noproblem with rotating only the engine 2 and taking-off in such a manner.Also in this case, based on the output map shown in FIG. 7, the torqueassist may be performed by driving the motor/generator 3.

[0081] Moreover, in the case of a larger throttle angle Th2, the drivertemporarily requires large torque and desires a rapid take-off, whereaswith rotation of only the engine 2, output torque OutPutTrq has a smoothgradient and a vehicle speed Speed shows slow acceleration as shown inFIG. 8. Under such circumstances, compared with the conventional controlmethod of canceling congested road control as shown in FIG. 18, outputtorque is largely weakened, and the driver feels a sense of discomfort.

[0082] Therefore, for a case in which the throttle angle reaches a valuelarger than a specified value, the motor control unit 12 immediatelyperforms torque assist to the engine 2 based on the output map shown inFIG. 7, and outputs only a part of the torque M/G Trq corresponding to apart of the under torque to the automatic speed change mechanism 5 sideas shown in FIG. 9. Consequently, the output torque OutPutTrq of thevehicle largely increases from the time of throttle actuation as shownby a solid line in FIG. 9, and concomitantly, the vehicle speed Speedalso rapidly increases, so that, regardless that the shift speed isfixed at 3RD because downshift is disabled, it is possible to provide anacceleration feeling intended by the driver.

[0083] Thus, by performing torque assist by the motor/generator 3, it ispossible without canceling congested road control to quickly meet atemporary torque request at a low torque output state where the vehicleis in a downshift disabling state (or, a state where the shifting lineis changed to a low speed side), and furthermore, since the low torqueoutput state of the vehicle is maintained, it is possible to continuecongested road control, that is, a take-off operation from a high shiftspeed maintained until then even when a jam state continues, and it ispossible to prevent busy shifting and an occurrence of a sense ofjumping out as in a take-off from a normal low shift speed (that is, astate where the gear ratio is small).

[0084] By increasing the amount of torque assist by the motor/generator3, it is possible to set a shift speed used for a take-off to a higherspeed, and it is possible to further prevent busy shifting.

[0085] Moreover, at step S31, a case where the oil temperature of theengine 2 is equal to or less than the defined value ‘6’, or the watertemperature of the engine 2 is equal to or less than the defined value‘7’, or the oil temperature of the automatic speed change mechanism 5 isequal to or less than the defined value ‘8’, or the SOC of the batteryis equal to or less than the defined value ‘9’ is a case wherewarming-up is necessary because the engine 2 and the automatic speedchange mechanism 5 have just been actuated, and furthermore, a casewhere the SOC of the battery is low and torque assist by the use of themotor/generator 3 cannot be sufficiently carried out, so that control isexecuted in such a manner that warming-up of the engine 2 and thecharging operation to increase the SOC of the battery take priority overa busy-shifting prevention operation.

[0086] Thereby, at step S37, idle stop control for stopping the engine 2when the vehicle stops is disabled, and the charging operation of thebattery takes priority. This step may not be executed for a case inwhich the amount of the SOC of the battery is sufficient.

[0087] Next, at step S38, for a case in which the shifting line ischanged to the low output torque side because of execution of step S33and so on described before, the setting of the shifting line is broughtback to a normal shifting line shown by the solid line of FIG. 6. For acase in which downshift to a lower speed is disabled at step S33 and soon, the disabling is canceled, and a normal shifting state is returnedto.

[0088] Next, at step S39, for a case in which conditions of idle stopare changed at step S32 and so on, conditions of normal idle stop arerestored at step S40, whereby the engine is set to easily start fromwhen stopped, and the motor/generator 3 is set so as not to be used whenpossible. For a case in which idle stop is disabled at step S37, thisstep is meaningless, and therefore, skipped.

[0089] When the running state of the vehicle is thus returned from astate of congested road control to a normal running state in theshifting line and idle stop control, it is judged at step S41 whetherpresent engine torque is more than a defined value ‘10’ or not. Thisdefined value ‘10’ is a torque value at which there is no jump-outtorque, and is the value of the output torque when in 3RD. For a case inwhich present engine torque is less than the defined value ‘10’ andthere is no jump-out torque, there is no wasteful torque production fromthe engine, and therefore, it is impossible to use such jump-out torqueand use the motor/generator 3 for a regenerating operation, so thecongested road control program JCP is ended.

[0090] Moreover, for a case in which present engine torque is over thedefined value ‘10’ and there is some jump-out torque at step S41, avalue of the defined value ‘10’, that is, a part of the torque necessaryfor moving the vehicle is derived from the present engine torque and apart of the jump-out torque which does not contribute to movement of thevehicle is calculated as motor/generator (M/G) torque at the time ofregenerating the motor/generator 3 at step S42.

[0091] At step S43, regarding the motor/generator (M/G) torque found atstep S42, it is judged whether the torque exceeds a torque limitationvalue of the motor/generator or not referring to a regeneration sidemotor torque output limitation value map MAP shown in FIG. 10.

[0092] For a case in which the motor/generator (M/G) torque is over thetorque limitation value of FIG. 10, the motor/generator (M/G) torque atthe time of regeneration is set as a torque limitation value at stepS44. Then, at steps S4 and S46, a control operation of the output torqueof the vehicle is started, and a regenerating operation by themotor/generator 3 is performed.

[0093] In this case, as shown in FIG. 11, when the driver actuates thethrottle, the automatic transmission is caused to perform a normalshifting operation by the transmission control unit 15, the take-off isperformed from 1ST, output torque OutPutTrq including jump-out torque TQwith rapid torque increase is observed at the axels 45 l and 45 r, andfor a case in which torque control is not performed by themotor/generator 3, the vehicle speed is rapidly accelerated from astopped state, and a good driving feeling is not necessarily produced ona congested road where high acceleration is unnecessary. However, in astate where the water temperature and the oil temperature of the engineand the oil temperature in the automatic transmission are low, becausethe engine rotates at a high output, warming-up can be performed.

[0094] In the case of using the motor/generator 3 in a regeneratingoperation so as to absorb jump-out torque TQ as shown in FIG. 12, extrajump-out torque TQ is consumed for a power generating operation of themotor/generator 3 so as to contribute to improvement of the SOC of thebattery, and since the part of jump-out torque TQ is consumed by themotor/generator 3, a vehicle speed rises slowly from a stopped state asshown by a solid line in the drawing, and the vehicle can take-off insuch a behavior as if taking-off at a high shift speed suitable forrunning on a congested road. Moreover, it is possible to continue toperform a warming-up operation of the engine, and it is possible toobtain a good driving state.

[0095] Since the battery is consequently charged, it is possible todecrease the need to actuate the engine in order to charge the batteryat the time of idle stop control thereafter, and perform idle stopcontrol effectively.

[0096] Subsequently, an embodiment in which the above embodiment ispartly changed will be described with reference to the drawings. Theaforementioned automatic speed change mechanism is a stepped speedchange mechanism 5 which forms five forward speeds and one reverse speedby engagement states of the clutches C1 to C3, the brakes B1 to B5 andthe one-way clutches F1 and F2, for example, whereas in the embodimentdescribed below, a continuously variable speed change mechanism 5′ whichshifts by a belt and pulleys is applied to the present invention as anautomatic speed change mechanism. In the following description,description of the same parts as described in the aforementionedembodiment, except partial changes, will be omitted.

[0097]FIG. 13 is a skeleton view showing a continuously variable speedchange mechanism 5 as applied to the present invention. In the drawings,reference numeral 5′ denotes a continuously variable transmission (CVT)for a hybrid vehicle, which is constructed by attaching amotor/generator 3 to a belt type continuously variable transmissionprovided with a torque converter 4′, a forward/reverse switching unit70, a belt type continuously variable speed change unit 80 and adifferential unit 100. Moreover, the CVT 5′ is connected to an internalcombustion engine 2 (not shown in the drawings, while an output shaft 60is shown). In the CVT 1, the torque converter 4′, the forward/reverseswitching unit 70, a primary pulley 81 of the belt type continuouslyvariable speed change unit 80, and the motor/generator 3 are placed on afirst shaft in line with the internal combustion engine output shaft 60,and a secondary pulley 82 of the belt type continuously variable speedchange mechanism is placed on a second shaft in parallel with theaforementioned first shaft.

[0098] In a position overlapping a shaft direction of themotor/generator 3, a lock-up clutch 36′ made by a multi-plate clutch isplaced, an input portion of the lock-up clutch 36′ is coupled to theengine output shaft 60 and the motor/generator 3, and an output portionof the lock-up clutch is coupled to a turbine runner of the torqueconverter 4′ and an input shaft 61. Moreover, a stator of the torqueconverter 4′ is coupled to a mechanical oil pump 7 via a one-way clutch.

[0099] The forward/reverse switching unit 70 has a double-pinionplanetary gear 62, a reverse brake B1 and a direct clutch (a forwardclutch or an input clutch) C1. In the planetary gear 62, a sun gear Sthereof is coupled to the input shaft 61, and a carrier CR supportingfirst and second pinions P1 and P2 is coupled to the primary pulley 81of the belt type continuously variable speed change unit 80. Moreover, aring gear R is coupled to the aforementioned reverse brake B1, and thedirect clutch C1 is interposed between the carrier CR and the ring gearR.

[0100] On the other hand, the belt type continuously variable speedchange unit 80 is provided with the primary pulley 81 composed of afixed sheave 84 fixed to a primary shaft and a moving sheave 83supported by the shaft so as to be capable only of sliding, thesecondary pulley 82 composed of a fixed sheave 85 fixed to a secondaryshaft 63 and a moving sheave 86 supported by the shaft so as to becapable of sliding only, and a power transmission belt 87 made of metaland wound around both the pulleys.

[0101] Hydraulic actuators are placed at the back of the moving sheave83 on the primary side and at the back of the moving sheave 86 on thesecondary side, respectively, and when receiving a signal from theaforementioned transmission control unit 15, a hydraulic control unit 6causes these moving sheaves 83 and 86 to slide to thereby change apulley width of both the pulleys 81 and 82 and change a diameter of aholding face of the aforementioned belt 87, and controls a gear ratio(also referred to as ‘a pulley ratio’ hereafter) at will.

[0102] Between the above secondary shaft 63 and the differential unit100, a counter shaft 64 is supported to a case so as to be rotatable,and a large gear 91 and a small gear 92 are fixed to the counter shaft64. The large gear 91 is meshed with a gear 93 fixed to the secondaryshaft 63, and the small gear 92 is meshed with a gear 95 of thedifferential unit 100. The differential unit 100 transmits rotation of adifferential gear supported by a differential case and having the gear95 to left and right axles 101 l and 101 r via left and right sidegears, which are not shown in the drawings.

[0103] Since the hybrid vehicle having the continuously variable speedchange mechanism 5′ has a construction as described above, while thevehicle is running, the aforementioned vehicle control unit 13 executesthe congested road judgment program JJP shown in FIG. 4 at all times tojudge whether a present running state is congested road running or not,and in the case of a judgment as running on a congested road at present,executes a congested road control program JCP′. FIG. 14 is a flowchartshowing one example of the congested road control program, FIG. 15 is aview showing a relation of the throttle angle, the pulley ratio, thevehicle output and the vehicle speed when using torque assist by themotor/generator, and FIG. 16 is a view showing a relation of thethrottle angle, the pulley ratio, the vehicle output and the vehiclespeed when performing a regenerating operation by the motor/generator.

[0104] In the hybrid vehicle having the continuously variable speedchange mechanism 5′, the congested road judgment program JJP is the sameas that in the hybrid vehicle having the aforementioned stepped speedchange mechanism 5, and therefore, a description thereof will beomitted.

[0105] For a case in which the congested road judgment program JJP isperformed and the congested road judgment flag is turned ON, the vehiclecontrol unit 13 executes the congested road control program JCP′ shownin FIG. 14. Then, the congested road control program JCP, at step S50,checks whether the congested road judgment flag is ON or not, and atstep S51, judges whether the oil temperature of the engine 2 is equal toor more than a defined value ‘6’ (a temperature at which the engine oiltemperature reaches a normal temperature: for example, about 30° C.),whether the water temperature of the engine 2 is equal to or more than adefined value ‘7’ (a temperature at which the engine water temperaturereaches a normal temperature: for example, about 30° C.), whether theoil temperature of the automatic speed change mechanism 5′ is equal toor more than a defined value ‘8’ (a temperature at which the oiltemperature of the automatic speed change mechanism reaches a normaltemperature: for example, about 30° C.), and whether the SOC of thebattery is equal to or more than a defined value ‘9’ (a degree at whichthe torque assist described later can be performed several times at thetime of idle stop control: for example, about 40%), that is, judges astate of a drive portion of the hybrid vehicle.

[0106] More specifically, for a case in which the oil temperature of theengine 2 is over the defined value ‘6’, the water temperature of theengine 2 is over the defined value ‘7’, the oil temperature of theautomatic speed change mechanism 5 is over the defined value ‘8’ or theSOC of the battery is over the defined value ‘9’, the engine 2 is in anormal running state and the charge capacity of the battery driving themotor/generator 3 is sufficient, so that a busy-shifting preventionoperation by torque assist using the motor/generator 3 described lateris performed. Moreover, at step S51, a case where the oil temperature ofthe engine 2 is equal to or less than the defined value ‘6’, the watertemperature of the engine 2 is equal to or less than the defined value‘7’, the oil temperature of the automatic speed change mechanism 5 isequal to or less than the defined value ‘8’ or the SOC of the battery isequal to or less than the defined value ‘9’ (it is preferable to useAND/OR of a forming condition of these parameters in combination asnecessary according to a condition of the vehicle) is a case in whichwarming-up is necessary because the engine 2 and the automatic speedchange mechanism 5′ have just been actuated, and furthermore, a casewhere the SOC of the battery is low and torque assist using themotor/generator 3 cannot be sufficiently performed, so that control isexecuted in such a manner that warming-up of the engine 2 and a chargingoperation to increase the SOC of the battery take priority over abusy-shifting prevention operation as described later.

[0107] Here, busy shifting is not the frequent switching of a shiftspeed described regarding the aforementioned stepped speed changemechanism 5, but the frequent changing of the pulley width of the belttype continuously variable speed change unit 80 of the aforementionedcontinuously variable speed change mechanism 5′, that is, the frequentchanging of a gear ratio, whereby upshift/downshift is frequentlyrepeated.

[0108] In the case of performing a busy-shifting prevention operation bytorque assist using the motor/generator 3 at step S51, conditions at thetime of idle stop are changed at step S52. More specifically, variouskinds of parameters during idle stop which stop the engine 2 when thevehicle stops and stop the idling of engine 2 are changed, inconsideration of congested conditions, so that the engine is asdifficult to start as possible and the vehicle can run using themotor/generator 3 when it begins to move. Specifically, for example, anactuation condition of the engine 2 is changed from a vehicle speed of 0Km/h to 10 Km/h, and actuation of the engine 2 by brake-off is stopped.

[0109] Next, at step S53, a pulley ratio when the vehicle stops ischanged. More specifically, when the vehicle stops, a pulley width ofthe aforementioned belt type continuously variable speed change unit 80is changed and set not to a pulley width when the vehicle normally stopsbut to a pulley ratio (for example, 2.00) on an upshift side of a statewhere a pulley ratio is small (a gear ratio is large), whereby outputtorque from a driving source (the engine or the motor/generator) whenthe vehicle takes-off is made to be small. Subsequently, at step S54,downshift is disabled by the transmission control unit 15, that is,because it is set to the upshift side more than the pulley ratio that iscalculated from the shifting line view and the like in the normalrunning state, it is disabled so that the pulley ratio is not changed toa downshift side even when the vehicle takes-off.

[0110] Next, at step S56, output torque of the motor/generator 3 thatcorresponds to the throttle angle and the motor/generator revolution isfound from the torque output map of the motor/generator shown in FIG. 7.When the throttle angle and the revolution of the engine 2 (that is, therevolution of the motor/generator 3) at present are ascertained fromthis output map, the torque to assist by the motor/generator 3 isimmediately ascertained. Regarding output of the motor/generator 3,output torque may be found from the throttle angle and the vehiclespeed, or only from the throttle angle by the use of specified maps,respectively.

[0111] Next, at steps S57 and S58, the motor control unit 12 is directedto perform torque assist to the engine 2.

[0112] More specifically, for example, as shown in FIG. 15, both for acase in which a throttle angle becomes Th1 and for a case in which itbecomes Th2 larger than Th1 as a result of the throttle being actuatedin a congested road judgment flag ON state, as described regarding stepS54, downshift is disabled by the transmission control unit 15 becausethe congested road judgment flag is ON, and a pulley ratio is fixed to,for example, 2.00, which is a state where a gear ratio is large. Despitethe take-off at a pulley ratio of, for example, 2.00 regardless of thethrottle angle, because the take-off is on a congested road the take-offat low torque is slow.

[0113] In the case of a small throttle angle Th1, a driver is notintending to rapidly accelerate the vehicle, and therefore, there is noproblem with rotating only the engine 2 and taking-off in such a manner.Also in this case, based on the output map shown in FIG. 7, the torqueassist may be performed by driving the motor/generator 3.

[0114] Moreover, in the case of a larger throttle angle Th2, the drivertemporarily requires large torque and desires a rapid take-off, whereaswith rotation of only the engine 2, output torque OutPutTrq has a smoothgradient and a vehicle speed Speed shows slow acceleration as shown by abroken line in FIG. 9. Under such circumstances, compared with theconventional control method of canceling congested road control as shownin FIG. 18, output torque is largely weakened, and the driver feels asense of discomfort.

[0115] Therefore, for a case in which a throttle angle reaches a valuelarger than a specified value, the motor control unit 12 immediatelyperforms the torque assist to the engine 2 based on the output map shownin FIG. 7, and outputs only a part of the torque M/G Trq correspondingto a part of the under torque to the automatic speed change mechanism 5′side as shown by a solid line in FIG. 15. Consequently, as shown by thesolid line of FIG. 15, the output torque OutPutTrq of the vehiclelargely increases from a time of throttle actuation, and concomitantly,the vehicle speed Speed also rapidly increases, so that, regardless thatthe gear ratio is fixed to, for example, 2.00 because of downshiftdisabling, it is possible to provide an acceleration feeling intended bythe driver.

[0116] Thus, by performing torque assist by the motor/generator 3, it ispossible without canceling congested road control to quickly meet even atemporary torque request of a driver at a low torque output state wherea vehicle is in a downshift disabling state, and furthermore, since thelow torque output state of the vehicle is maintained, even when acongested state continues, it is possible to continue congested roadcontrol, that is, a take-off operation from a large gear ratiomaintained until then, and it is possible to prevent busy shifting andthe occurrence of a sense of jumping out as in a take-off from a normalstate of a small gear ratio.

[0117] By increasing the amount of torque assist by the motor/generator3, it is possible to set the gear ratio used for a take-off to a higherspeed (for example, a pulley ratio of 2.00 or less), and it is possibleto further prevent busy shifting.

[0118] Moreover, at step S51, a case in which the oil temperature of theengine 2 is equal to or less than the defined value ‘6’, or the watertemperature of the engine 2 is equal to or less than the defined value‘7’, or the oil temperature of the automatic speed change mechanism 5′is equal to or less than the defined value ‘8’ or the SOC of the batteryis equal to or less than the defined value ‘9’ is a case wherewarming-up is necessary because the engine 2 and the automatic speedchange mechanism 5′ have just been actuated, and a case in which the SOCof the battery is low and torque assist using the motor/generator 3cannot be sufficiently performed, so that control is executed in amanner that warming-up of the engine 2 and the charging operation toincrease the SOC of the battery take priority over a busy-shiftingprevention operation.

[0119] Thereby, at step S59, the idle stop control for stopping theengine 2 when the vehicle stops is disabled, and the operation forcharging the battery takes priority. This step may not be executed for acase in which the amount of the SOC of the battery is sufficient.

[0120] Next, at step S60, for a case in which a pulley ratio when thevehicle stops is changed to an upshift side with a pulley ratio of, forexample, 2.00 because of execution of step S53 and so on describedbefore, the setting is changed to a normal pulley ratio when the vehiclestops (for example, 2.42), and returns to a normal setting. Then, atstep S61, downshift is permitted, and for a case in which downshift isdisabled at step S54 and so on, the disabling is canceled, and a normalshifting state is returned to.

[0121] Next, at step S62, for a case in which conditions of idle stopare changed at step S52 and so on, conditions of normal idle stop arerestored at step S63, whereby the engine is set to easily start fromwhen stopped, and the motor/generator 3 is set so as not to be used whenpossible. For a case in which idle stop is disabled at step S59, thisstep is meaningless, and therefore, skipped.

[0122] When a running state of the vehicle is thus returned from acongested road control state to a normal running state in a change of apulley ratio and idle stop control, it is judged at step 64 whether thepresent engine torque exceeds a defined value ‘10’ or not. This definedvalue ‘10’ is a torque value of the level of no jump-out torque, and avalue of the level of output torque in the case of a pulley ratio of2.00, for example. For a case in which present engine torque is lessthan the defined value ‘10’ and there is no jump-out torque, there is nowasteful torque production from the engine, and therefore, it isimpossible to use such jump-out torque and use the motor/generator 3 forthe regenerating operation, so that the congested road control programJCP′ is ended.

[0123] Moreover, for a case in which the present engine torque is overthe defined value ‘10’ and there is some jump-out torque at step S64, avalue of the defined value ‘10’, that is, a part of the torque presentlyneeded to move the vehicle is derived from the present engine torque,and a part of jump-out torque which does not contribute to movement ofthe vehicle is calculated as motor/generator (M/G) torque at the time ofregenerating the motor/generator 3 at step S65.

[0124] At step S66, regarding the motor/generator (M/G) torque found atstep S65, referring to a regeneration side motor torque outputlimitation value map MAP shown in FIG. 10, it is judged whether or notthe torque exceeds a torque limitation value of the motor/generator.

[0125] For a case in which the motor/generator (M/G) torque is over thetorque limitation value of FIG. 10, motor/generator (M/G) torque at thetime of regeneration is set as a torque limitation value at step S67.Then, at steps S68 and S69, a control operation of output torque of thevehicle is started, and a regenerating operation by the motor/generator3 is performed.

[0126] In this case, as shown in FIG. 16, when the driver actuates thethrottle, the automatic transmission is caused to perform a normalshifting operation by the transmission control unit 15, a take-off isperformed from a pulley ratio of, for example, 2.42, output torqueOutPutTrq including jump-out torque TQ with a rapid torque increase isobserved at the axels 101 l and 101 r as shown by a broken line in FIG.16, and for a case in which torque control is not performed by themotor/generator 3, the vehicle speed is rapidly accelerated from a stopstate, so that a good driving feeling is not necessarily produced on acongested road where high acceleration is unnecessary. However, in astate where the water temperature and the oil temperature of the engineand the oil temperature in the automatic transmission are low, becausethe engine rotates at a high output, warming-up can be performed.

[0127] In a case in which the motor/generator 3 is used in aregenerating operation so as to absorb jump-out torque TQ as shown by asolid line in FIG. 16, extra jump-out torque TQ is consumed for a powergenerating operation of the motor/generator 3 so as to contribute toimprovement of the SOC of the battery, and since the jump-out torque TQis consumed by the motor/generator 3, a vehicle speed rises slowly froma stop state as shown by the solid line in the drawing, and the vehiclecan take-off in such a behavior as if taking-off in a state of a largegear ratio suitable for running on a congested road. Moreover, awarming-up operation of the engine can be performed as it is, and a gooddriving state can be obtained.

[0128] Since the battery is consequently charged, it is possible todecrease the need to start the engine to charge the battery at the timeof idle stop control thereafter, and effectively perform idle stopcontrol.

[0129] Next, effects of the embodiments will be described.

[0130] According to the embodiments, since the under torque replenishingmeans replenishes a part of the under torque M/G Trq of the drivingsource (refer to FIGS. 9 and 15) by the motor/generator drive at thetime of temporary acceleration during congested road running, even for acase in which a temporary high acceleration take-off request (forexample, the throttle angle Th2 in FIG. 9 and the throttle angle Th2 inFIG. 15) is made during congested road running, it is possible toperform a take-off operation without a sense of discomfort in the formof maintaining a take-off operation from a state where the gear ratio ofthe automatic transmission is large. Also, consequently, since there isno need to cancel congested road control, a take-off from a state wherea gear ratio of the automatic transmission is small is prevented, andbusy shifting is prevented.

[0131] Moreover, since the temporary acceleration judging means judgeswhether or not to maintain a judgment of congested road running by thecongested road judging means for a case in which a temporary highacceleration take-off request (for example, the throttle angle Th2 inFIG. 9 and the throttle angle Th2 in FIG. 15) is made, the cancellationof the congested road judgment simply at a time when the highacceleration take-off request occurs is prevented, and take-off controlwith even less sense of discomfort is enabled.

[0132] Moreover, it is possible to easily find torque to replenish bythe driving of motor/generator from the output map of themotor/generator that corresponds to the throttle angle (for example,refer to FIG. 7), and control is facilitated.

[0133] Furthermore, it is possible to apply the output map to a drivingcondition of the vehicle.

[0134] Moreover, since the vehicle control unit 13 (for example, stepS32 of the congested road control program JCP and step S52 of thecongested road control program JCP′) that serves as the actuationcontrol means during congestion shifts actuation conditions of theinternal combustion engine to a high vehicle speed side while a judgmentof congested road running is maintained by the congested road judgingmeans, it is difficult to activate the internal combustion engine, andthereby because torque assist by the motor/generator is enabled, theinternal combustion engine can be activated in a state where a gearratio of the automatic transmission is large, and it is possible toprevent busy shifting.

[0135] On the other hand, according to the embodiments, for a case inwhich the congested road judging means judges that the vehicle isrunning on a congested road, it is possible at the time of take-off bythe internal combustion engine to cause the automatic transmission toperform normal shifting and perform a regenerating operation by drivingthe motor/generator with extra torque produced from the internalcombustion engine when taking-off. By charging the battery and ensuringa sufficient SOC, it is possible to effectively perform idle stopcontrol, which is a characteristic of a hybrid vehicle.

[0136] Moreover, because the vehicle control unit 13 that serves as theidle stop control disabling means (for example, step S37 of thecongested road control program JCP and step S59 of the congested roadcontrol program JCP′) disables idle stop control during congested roadrunning, it is possible to effectively charge the battery.

[0137] Furthermore, since the regeneration control means is driven whenthe SOC monitored by the SOC monitoring means becomes smaller than aspecified value, the battery is charged by regeneration of themotor/generator only when necessary. Therefore, when the SOC is largeand there is no need to charge, it is possible to perform idle stopcontrol, and it is possible to maximize a feature of a hybrid vehicle.

[0138] Moreover, according to the embodiments, since the vehicle controlunit 13 serving as actuation control switching means (for example, thecongested road control program JCP and the congested road controlprogram JCP′) selects and executes a regenerating operation or anoperation of replenishing the under torque in accordance with awarming-up state of the internal combustion engine and the automatictransmission, optimum control responsive to a state of the vehicle isenabled.

[0139] Furthermore, since it is judged from at least one of the oiltemperature and the water temperature of the internal combustion engineand the oil temperature of the automatic transmission whether theinternal combustion engine and the automatic transmission are in awarming-up state or not, an appropriate judgment is enabled.

[0140] Moreover, according to the embodiments, since the actuationcontrol switching means controls so as to execute the regeneratingoperation by the regeneration control means when the vehicle takes-offduring congested road running for a case in which the SOC of the batteryis judged as being equal to or less than a defined value, and execute anoperation for replenishing the under torque by the under torquereplenishing means when the vehicle takes-off during congested roadrunning for a case in which the SOC of the battery is judged as beingequal to or more than the defined value, appropriate control is enabledin response to the battery state.

[0141] Moreover, since the automatic stepped transmission 5 has aplurality of friction engagement elements C1, C2, C3, B1, B2, B3, B4,B5, F1 and F2 and the gear mechanisms 30 and 40 forming a plurality ofshift speeds that shift input rotation based on an engagement state ofthe friction engagement elements, it is possible to differentiate thegear ratio by switching the shift speeds. As a result, combined with thedrive of the motor/generator, it is possible, for example, to preventbusy shifting and charge the battery.

[0142] Moreover, since the automatic continuously variable transmission5′ has a pair of pulleys 81 and 82 and the power transmission belt 87held tight by the pulleys 81 and 82, it is possible to differentiate thegear ratio based on a pulley width of the pulleys 81 and 82. As aresult, combined with the drive of the motor/generator, it is possible,for example, to prevent busy shifting and charge the battery.

INDUSTRIAL APPLICABILITY

[0143] As described above, the control apparatus of a hybrid vehiclerelating to the present invention is useful as a control apparatus of ahybrid vehicle such as a car, a truck and a bus, and specificallysuitable for a use as a control apparatus in a vehicle which requiresprevention of busy shifting in congested road running and an appropriateregenerating operation.

What is claimed is:
 1. A control apparatus for a hybrid vehicle in whichan internal combustion engine and a motor/generator connected to theinternal combustion engine are used as a driving source, an automatictransmission connected to the driving source is disposed, axles areconnected to said automatic transmission, a sensor for detecting arunning state of the vehicle is disposed, a congested road judging meansfor judging whether the vehicle is running on a congested road or notbased on output from said sensor is provided, and a take-off controlmeans for controlling so as to cause to take-off from a state where agear ratio of the automatic transmission is large at the time oftaking-off in the case of being judged by said congested road judgingmeans as running on a congested road and controlling so as to cause totake-off from a state where a gear ratio of the automatic transmissionis small at the time of taking-off in the case of being not judged asrunning on a congested road is provided, wherein the control apparatusof the hybrid vehicle is constructed so as to have under torquereplenishing means which replenishes, by driving of saidmotor/generator, a part of an under torque of said driving source arisenwhen caused to take-off from a state where a gear ratio of the automatictransmission is large by said take-off control means, for a case inwhich a temporary high acceleration take-off request is made while ajudgment of congested road running by said congested road judging meansis maintained.
 2. The control apparatus of the hybrid vehicle accordingto claim 1, constructed so that said congested road judging means isprovided with temporary acceleration judging means which judges whetherto maintain a judgment of congested road running by said congested roadjudging means or not for a case in which a temporary accelerationtake-off state during congested road running develops.
 3. The controlapparatus of the hybrid vehicle according to claim 1, characterized inthat the under torque replenishing means has an output map of themotor/generator associated with a throttle angle and determines torqueto replenish by driving of said motor/generator based on the output map.4. The control apparatus of the hybrid vehicle according to claim 3,wherein said output map has an output map of the motor/generatorassociated with a throttle angle and a vehicle speed.
 5. The controlapparatus of the hybrid vehicle according to claim 3, wherein saidoutput map has an output map of the motor/generator associated with athrottle angle and a motor revolution.
 6. The control apparatus of thehybrid vehicle according to claim 1, constructed so as to have jam-timeactuation control means which shifts an actuating condition of saidinternal combustion engine to a high vehicle speed side while a judgmentof congested road running is maintained by said congested road judgingmeans.
 7. The control apparatus of the hybrid vehicle according to claim1, characterized in that said automatic transmission is an automaticstepped transmission which has a plurality of friction engagementelements and a gear mechanism forming a plurality of shift speedsshifting input rotation based on an engagement state of said frictionengagement elements and differentiates a gear ratio by switching saidshift speeds.
 8. The control apparatus of the hybrid vehicle accordingto claim 1, characterized in that said automatic transmission is anautomatic continuously variable transmission which has a pair of pulleysand a power transmission belt held tight by said pulleys anddifferentiates a gear ratio based on a pulley width of said pulleys. 9.In a hybrid vehicle in which an internal combustion engine and amotor/generator connected to the internal combustion engine are used asa driving source, an automatic transmission connected to the drivingsource is disposed, axles are connected to said automatic transmission,a sensor for detecting a running state of the vehicle is disposed, andcongested road judging means for judging whether the vehicle is runningon a congested road or not based on output from said sensor, a controlapparatus of the hybrid vehicle, constructed so as to have regenerationcontrol means which causes said automatic transmission to perform normalshifting at the time of take-off by said internal combustion engine andconsequently causes to perform a regenerating operation by driving saidmotor/generator with extra torque produced from said internal combustionengine at the time of take-off, for a case in which said congested roadjudging means judges that the vehicle is running on a congested road.10. The control apparatus of the hybrid vehicle according to claim 9,constructed so as to have idle stop control disabling means whichdisables control of stopping said internal combustion engine when thevehicle stops for a case in which said congested road judging meansjudges that the vehicle is running on a congested road.
 11. The controlapparatus of the hybrid vehicle according to claim 9, characterized inthat an SOC monitoring means which monitors an SOC of the battery isdisposed and said regeneration control means is driven for a case inwhich the SOC monitored by the SOC monitoring means is less than aspecified value.
 12. The control apparatus of the hybrid vehicleaccording to claim 9, characterized in that said automatic transmissionis an automatic stepped transmission which has a plurality of frictionengagement elements and a gear mechanism forming a plurality of shiftspeeds that shift input rotation based on an engagement state of thefriction engagement elements and differentiates a gear ratio byswitching said shift speeds.
 13. The control apparatus of the hybridvehicle according to claim 9, characterized in that said automatictransmission is an automatic continuously variable transmission whichhas a pair of pulleys and a power transmission belt held tight by saidpulleys and differentiates a gear ratio based on a pulley width of saidpulleys.
 14. The control apparatus of the hybrid vehicle, constructed soas to have: a running state judging means which judges whether theinternal combustion engine and the automatic transmission are in awarming-up state or not; and an actuation control switching means whichcontrols so as to execute a regenerating operation by the regenerationcontrol means according to claim 9 when the vehicle takes-off duringcongested road running for a case in which said running state judgingmeans judges said internal combustion engine and automatic transmissionas being in a warming-up state, and execute an operation of replenishingunder torque by the under torque replenishing means according to claim 1when the vehicle takes-off during congested road running for a case inwhich said running state judging means judges said internal combustionengine and automatic transmission as being in a normal running state.15. The control apparatus of the hybrid vehicle according to claim 14,characterized in that the running state judging means judges from atleast one of an oil temperature and water temperature of the internalcombustion engine and an oil temperature of the automatic transmissionwhether said internal combustion engine and automatic transmission arein a warming-up state or not.
 16. The control apparatus of the hybridvehicle according to claim 14 characterized in that said automatictransmission is an automatic stepped transmission which has a pluralityof friction engagement elements and a gear mechanism forming a pluralityof shift speeds that shift input rotation based on an engagement stateof said friction engagement elements and differentiates a gear ratio byswitching said shift speeds.
 17. The control apparatus of the hybridvehicle according to claim 14, characterized in that said automatictransmission is an automatic continuously variable transmission whichhas a pair of pulleys and a power transmission belt held tight by saidpulleys and differentiates a gear ratio based on a pulley width of saidpulleys.
 18. The control apparatus of the hybrid vehicle, constructed soas to have: battery state judging means which judges a state of an SOCof a battery driving the motor/generator; and an actuation controlswitching means which controls so as to execute a regenerating operationby the regeneration control means according to claim 9 when the vehicletakes-off during congested road running for a case in which said batterystate judging means judges an SOC of said battery as being equal to orless than a defined value, and execute an operation of replenishingunder torque by the under torque replenishing means according to claim 1when the vehicle takes-off during congested road running in the case ofjudging the SOC of said battery as being equal to or more than thedefined value.
 19. The control apparatus of the hybrid vehicle accordingto claim 18, characterized in that said automatic transmission is anautomatic stepped transmission which has a plurality of frictionengagement elements and a gear mechanism forming a plurality of shiftspeeds shifting input rotation based on an engagement state of thefriction engagement elements and differentiates a gear ratio byswitching said shift speeds.
 20. The control apparatus of the hybridvehicle according to claim 18, characterized in that said automatictransmission is an automatic continuously variable transmission whichhas a pair of pulleys and a power transmission belt held tight by saidpulleys and differentiates a gear ratio based on a pulley width of saidpulleys.